1. Field of the Invention
This invention relates to a method and system for scribing and separating semiconductor chips formed on a semiconductor wafer.
2. Brief Description of the Prior Art
Chips formed on a single wafer of semiconductor material have generally been scribed and separated in the prior art by one of several available procedures. These prior art procedures generally provide for attachment of the wafer to an adhesive handling film with subsequent fracturing taking place along "streets" between rows and columns of chips to separate the chips. The chips are then removed from the handling film and processed in standard manner.
Fracturing of the wafer has generally been accomplished by (1) laser scribing a depression in the wafer along the "streets" and then breaking the wafer the rest of the way, (2) sawing a depression in the wafer along the "streets and then breaking the wafer the rest of the way, or (3) sawing entirely through the wafer along the "streets".
A problem arising from the above described prior art techniques has been the large amount of semiconductor material or chip surface area wasted due to the large "street" widths required in order to prevent damage to chips during chip separation. In the case of fracturing by the procedures listed above as (1) and (2), there is the possibility that the break in the wafer below the depression will not be straight, resulting in chips of non-uniform dimensions. Also, sawing can causes fractures at the wafer surface, this being a source of defects and decreased yields when sawing takes place at the surface containing the electrical components.